1. Field of the Invention
The present invention relates to a method of, and an apparatus for manufacturing a plurality of kinds of elongate articles, e.g. molding members for automobiles and the like, or segments of such molding members.
2. Description of the Related Art
A variety of molding members are used widely, such as front or rear window molding members, body side molding members, etc., for automobiles, which are generally composed of extruded synthetic resin material. Among others, Japanese Patent Application Laid-open Publication No. 61-135,824 discloses a windshield molding member which includes an upper segment to extend along an upper edge of a windshield plate, a pair of side segments to extend along side edges of the windshield plate, and a pair of corner segments connecting the upper and side segments into an integral component.
In the known molding members mentioned above, the upper and side segments are composed of synthetic resin material extruded into respectively predetermined cross-sections which are basically the same width, and slightly different from each other. More particularly, the upper segment includes a main body which is provided with a first lip section to be engaged with the other surface of a windshield plate, a second lip section to be engaged with the outer surface of vehicle body panel, and a leg section to be inserted into a gap between the edge of the windshield plate and the body panel. The leg section has fins on both sides to be engaged with the periphery of the windshield plate and the body panel, respectively, so as to prevent undesirable withdrawal of the lip section out of the gap. The upper segment may have an ornamental film and a core element arranged in the main body and the leg section, respectively, depending upon ornamental and/or functional requirements. On the other hand, the side segment has a basic cross-section which is the same as that of the upper segment, as well as an additional section in the form of a ridge on the first lip section, which is adapted to define a weir or channel extending along a side edge of the windshield plate. The upper segment without ridge serves to realize a flush surface of the automobile body along the upper edge of the windshield plate, while the ridge on the side segment achieves the functions to guide rain water on the windshield plate to flow along the weir or channel, and to thereby prevent the rain water from flowing onto a side window across the side segment and neighboring body panel portion (or pillar) to disturb the driver's sight which is through the side windows.
In order to manufacture the upper and side segments of mutually different cross-section, it has been a conventional practice to prepare and selectively use two extrusion die plates, one for the upper segments and the other for the side segments, which are expensive and make it thus difficult to reduce the production cost of the molding members. Not only the exchange of the die plates requires troublesome and time-consuming manual operations, but also it is necessary to carry out a test-running extrusion after each exchange of the die plate, in order to confirm that the synthetic resin material can be stably extruded into a continuous body with a desired accuracy of the cross-section. Moreover, the synthetic resin material as well as the ornamental film and the core element, which have been extruded from the die plate during the test-running extrusion period, have to be disposed of as industrial waste materials. Alternate use of different die plates to produce different elongate articles of basically the same cross-section proved to be disadvantageous in many cases, particularly when a relatively small number of elongate articles of various cross-sections are to be produced in each production lot.